It is desirable when surgery is required, or in any medical procedures, to be as minimally invasive as possible. The well being of the patient and speed of recovery are often dependent on the degree to which a procedure is quickly and accurately accomplished, with as little damage to the body and with as little blood loss as possible. For this reason laparoscopic and other minimally invasive surgical procedures have gained considerable favor among health care professionals.
Providing surgical procedures with minimally invasive openings from the skin, or other surface, to the point of surgical interest will tend to aid in the rapid recovery of the patient. The use of modern surgical techniques, including laparoscopy, fluoroscopy, MRI, CT and other methods of viewing and working within the operating theater, have made a significant difference in the quality and speed of patient recovery.
However, techniques for accomplishing such surgery have often been hampered by the need to provide a stable opening from an outer surface, such as the skin or the muscle through to the area of surgical interest, without causing damage to tissue there between. Presently it is necessary to form an incision and then, by using mechanical retractors, pull back and hold an opening open throughout the surgical procedure. Such use of mechanical retractors tends to cause damage to skin surfaces and increases the time of recovery and the pain that the patient feels. Further, the size of the incision needed to create the appropriately sized opening through which surgery will proceed can increase the amount of bleeding and oozing in the wound, cause tears in skin and muscle and provide a site for post-operative infections.
One method for creating a smaller surgical corridor without using claw-like mechanical retractors is through the use of sequential dilator tubes. In this method, a small incision is made and a small post is first inserted to the necessary depth, after which a series of larger and larger tubes is forced into place over the initial guide post. Finally, the central tubes and post are removed, leaving only the outer tube as a corridor through which to perform minimally invasive surgery. This method, embodied by the Metr'x system (Medtronic), has the problem that each additional tube can potentially damage the surrounding musculature, connective tissue, and nerves through a shearing action as it is slid into place, especially as the tension on the retracted tissues becomes greater and greater with each dilation.
It is desirable to conduct a surgical procedure using modern minimally invasive methods while providing a stable opening that can be made with minimal damage to the surrounding tissue.